Can anybody help with our strange problem with our CO2 anaesthetising
set-up? We have a dual-stage regulator fixed to a CO2 cylinder, and run
two lines off it. Each line bubbles through a separate side arm flask of
water to humidify the gas. The problem is that when the cylinder is turned
off, we get water sucking back into the tubing from the flask, sometimes
nearly all the way back to the regulator.
This happens whether or not the cylinder is also turned off at the needle
valve. It also happens in both lines, even if one of those lines is
switched off. We can solve the problem by breaking the line at the
branch-point, but we'd rather not have to do that every time we turn the
gas off!
I have worked with an almost identical set up in a previous lab, and never
seen this problem, and cylinder and regulator suppliers can shed no light
upon it. Has anyone else experienced this? Any suggestions?
Thanks for any help,
Emma